220—12 INDIAN TERTIARY AND POST-TERTIARY VERTEBRATA. 
From the middle eocene of Bracklesham Gharialis dixoni, Owen/ has been 
described on the evidence of portions of the mandible and vertebrae ; the teeth are 
larger, placed farther apart, and less compressed than in G. gangeticus, while there 
are more distinctly defined interdental pits in the hinder part of the mandibular 
symphysis. 
The upper cretaceous pisolite of Mont Aimd (Marne), France, has yielded the 
so-called G. macrorhynchus (Blainville),^ which, as stated above,® has been referred on 
what appear to be somewhat insufficient grounds to the American fossil genus 
Thoracosaurus. The cranium has the extremity of the rostrum expanded, and is so 
like that of G. gangeticus, that, in the apparent absence of any evidence as to the 
presence or absence of a prelachrynial vacuity, the writer prefers to retain it 
provisionally in the existing genus. The anterior border of the orbit is not 
prominent. 
Most of the N. American upper cretaceous forms described under the name of 
IIolops'^ seem to be known merely by vertebrae. Numerous Indian fossil forms are 
described in the sequel which indicate that the genus formerly attained a great 
development in that country. The occurrence of these fossil forms, and the apparent 
absence of any species in the tertiaries of Europe of later date than the middle 
eocene, seems to indicate that the genus migrated eastwards from Europe during the 
tertiary period. The occurrence of Tomistoma in the reputed miocene of the 
Maltese Islands and lower Austria seems to indicate a similar migration of that 
genus. 
Group A, — No pits in the cranial rostrum for any of the mandibular teeth. 
Species 1. Gharialis gangeticus (Gmelin®). 
Syn. Lacerta gangetica^ Gmelin.® Crocodilus longirostris, Schneider.'^ 
Crocodilus gangeticus^ Cuvier.^ Crocodilus tenuirostris, Cuvier.® 
Leptorhynchus clifti., Meyer.“ Leptorhynchus gangeticus^ Auct. 
History of fossil form. — The first record of the occurrence of a fossil gharial in 
the Siwaliks is by Clift,“ who described some remains obtained by Crawfurd in 
Burma, and regarded them as allied to, or identical with, the existing species ; on 
these specimens Meyer’s Leptorhynchus clifti was founded. At a later date more perfect 
remains were described and figured by Cautley,^® from the Siwalik Hills, who 
referred them to the existing species. In his “ Catalogue of Fossil Vertebrata 
in the Museum of the Asiatic Society of Bengal ” (p. 165), Falconer confidently 
identifies a cranium from the Siwalik Hills with the existing species. 
Crania. — The British Museum possesses a considerable number of imperfect 
crania (some of which have the mandible attached) from the Siwalik Hills, of which 
1 “ Reptiles of the London Clay, etc.,” pt. 2. p. 46, pi. X. 
2 Fitfs Gervais “ Zool. et Pal. Franqaises,” 2nd ed. p. 447. pi. LIX. 3 Page 211. 4 Vide supra j)a.ge 211. 
5 “ Systema Naturae,” vol. I. pt. 3. p. 1057 (1789). Lacerta. 6 Loo. cit. 
7 ‘‘ Historia Amphibiorum,” p. 160. (1799-1801). 8 ‘ Ann. d. Museum,’ vol. X. p. 66 (1807j. 9 Loc. cit. 
10 “ Palaeologica,” p. 108 (1832). H ‘Trans. Geol. Soc,’ ser. 2. vol. II. pt. 3. p. 375. (1828) 
12 ‘ Asiatic Researches,’ vol. XIX. pp. 32-38, pi. III. (1836) 
